This invention relates generally to micro- and nano-encapsulation methods, particularly for synthesizing magnetic microparticles, for use in biomedical or other applications.
Chemically cross-linked materials have been used to form microparticles. The cross-linkable material forming the matrix can be a synthetic polymer or a natural polymer or protein, for example. The microparticles formed with these materials have been used for biomedical applications, primarily in the areas of drug delivery, immunoassay, and cell separation technologies. Chatterjee, et al., J. Mag. Magn. Mat. 225:21 (2001) discloses a method of forming encapsulated particles by dissolving a polymer and a particular inorganic particle in an aqueous solvent, forming an oil-in-water emulsion, and stabilizing the particles using chemical cross-linking. The stabilization by chemical cross-linking can undesirably permit agglomeration. It therefore would be desirable to avoid using a chemical cross-linker in a process for forming microparticles. It would be particularly desirable to make such nanoparticles without requiring an emulsion polymerization reaction.